A Novel Technique for Laryngotracheal Reconstruction for Idiopathic Subglottic Stenosis

Idiopathic subglottic stenosis is the most challenging condition in the field of upper airway reconstruction. We describe a successful novel technique for enlarging the airway space at the site of the laryngotracheal anastomosis in very high-level reconstructions

Induction, immobilization, modification and natural inhibitors of α-glucosidase from Penicillum chrysogenum

α-glucosidase (EC: 3.2.1.20) was isolated from Penicillum chrysogenum. The enzyme was enhanced by plant growth regulators such as gibberellic acid (GA3), benzylaminopurine (BAP) and kinetin. Dansyl chloride inhibited the enzyme at 1, 2, 3, 4 and 5 mM with T0.5 67, 52.2, 34.4 and 23.3 min, respectively. The substrate offered partial protection for the enzyme against dansyl chloride inhibition. The enzyme was activated by Ca2+ and Mg2+. However, Pb2+, Cd2+, Zn2+, Ni2+ and Hg2+ inhibited α-glucosidase activity. The enzyme was immobilized on Ca alginate and the optimal concentration for 3% w/v. The optimal concentration of CaCl2 was recorded at 3 mM. The optimal CaCl2 concentration and the optimum time for immobilization was 3mM and 4hr. The enzyme was inhibited by aqueous extracts of Datura stramonium, Trigonella foenum-graecum, Hyoscymus muticus and Cynodon dactylon. The IC50 values for the four extracts were 59.1, 73.6, 68.5 and 77.1 µg ml-1, respectively

Development of novel formulations to enhance in vivo transdermal permeation of tocopherol

Tocopherol represents a big challenge for transdermal permeation owing to its extreme hydrophobicity and large molecular mass. The aim of the present study was to develop alpha-tocopherol (T) topical formulations and evaluate the ex vivo and in vivo permeation. Franz diffusion cells were used for the ex vivo permeation, and neonatal rats were used for in vivo permeation. Seven gel formulations and 21 liquid formulations were investigated for physical stability, viscosity and permeation of T. Analysis of T was performed by a validated HPLC method using a UV detector.The ex vivo permeation from gel and emulsion formulations was very poor (0.001–0.015 %). The highest permeation was observed from monophasic liquid formulations containing dimethyl sulfuxide (DMSO), tocopheryl polyethylene glycols (TPGs), propylene glycol, ethanol, and 9.5 % T. The in vivo results demonstrated higher retention in the epidermis compared to subcutaneous tissues; 1377 and 1.13 µg g–1, respectively. Increasing T concentration from 4.8 to 9.5 % did not increase the amount permeated or % of T retained. It was concluded that simple solutions of T in presence of DMSO and TPGs are more promising systems for effective transdermal permeation; compared to gel, emulsion or oleaginous systems

Radiation pattern control of microstrip antenna in elevation and azimuth planes using EBG and pin diode.

An important issue in wireless communication systems, which is related to the antenna gain degradation in case of changing the main direction of the antenna radiation pattern, this variation is not approval in many communications systems. In order to improve antenna radiation performances, Electromagnetic band gap (EBG) - antenna with radiation pattern control capability is presented. Mushroom-like EBG structure for suppressing surface waves has been combined, with the switching diode to produce the radiation pattern control with improving antenna characteristics of gain, directivity and efficiency. EBG of several cells are surrounded the patch antenna and placed symmetrically for the two opposite sides, generating different radiation patterns control ability in both the elevation (E) (-20° < φ < 20°) and azimuth (Z) planes (−18° < θ < 18°). At the ground plane of antenna the diodes have been switched ON and OFF states, the EBG sector properties in stop band (connecting vias) and pass band (disconnecting vias) are altered. Using CST Microwave Studio (CST MWS) the results show the flexibility in radiation pattern control for the Z and E planes using only four diodes. Antenna directivity of 10 dBi, gain 9.86 dB and efficiency 96.5% at the operating frequency of 6 GHz, more results for all direction has been stated in Table1. Significantly, unlike a conventional beam steering, this method does not suffering from gain degradation and the main lobe gain is approximately constant for all steerig angles

Novel design of triple-bands EBG

This paper presents a novel design for a triple band electromagnetic band gap (EBG) structures that provides three band gaps, with operating frequency of below 10 GHz, while the ordinary mushroom like EBG structure gives only one band gap. Complexity reduction (reduce the number of unit cells and Vias) was achieved by replacing each four cells of the Mushroom like EBG by the one of double slotted type EBG (DSTEBG) or triple side slotted EBG (TSSEBG). The Mushroom like EBG was further modified by increasing its size and inserting the slots to gain more capacitance and inductance which resulted into triple band stop.The new designs wer compared with bandwidths expressed by other EBGs and -20 dB cut-off frequencies. The size of EBG element and the gap between EBG elements, and slot width were investigated to analyse their effect on the transmission response. The structures were designed from 2.54 mm Rogers RT/Duroid 6010 substrate with relative permittivity of 10.2 and loss tangent of 0.0023. Among the investigated EBGs, the single band mushroom like EBG and the triple band of the TSSEBG demonstrated better bandwidth and lower resonance frequency performance, whereas the DSTEBG showed larger bandwidth for the first and third band. The proposed EBGs could be useful in the antenna design and other microwave circuits

Side lobe reduction in array antenna by using novel design of EBG

A novel design of EBG is used to replace the mushroom like EBG for surrounding the array patch antenna. In order to improve its radiation performances, Electromagnetic band stop for reducing the surface waves effects is presented. The novel design of Triple Side Slotted EBG (TSSEBG) showed an improvement in the antenna efficiency, directivity and gain as compared to the reference antenna without using EBG, due to reduce the surface waves effects which leads to decrease the side lobes. TSSEBG has been introduced by some modifications in conventional mushroom-like EBG structure. Reducing the complexity was achieved by reducing the number of unit cells and vias, in case of used TSSEBG instead of mushroom like EBG. Additionally, the TSSEBG provided triple band gap compared with mushroom like EBG structure which had only one band gap frequency at 6 GHz. The placement of TSSEBG is a flexible structure which provides a good choice in the antenna applications. The simulation results of array patch antenna with and without mushroom like EBG and TSSEBG are arranged in Table 1. This structure has vast applications in satellite communications

Experimental investigation on viscosity of nanofluids prepared from banana fibre - nanoparticles

In this research for the first time, banana-fibre nanoparticles produced for nanofluid application and the viscosity of resultant nanofluids were measured.A Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM) were used to analyzethe sizes of the particles produced(200nm). This paper presents new findings on the synthesis of natural fibre to obtain nanoparticles and subsequently produced nanofluids. Nanofluids are prepared by dispersing Banana fibre- nanoparticles in deionized water.An ultrasonic sonicator was used to ensure proper mixtures of different volume fractions (0.3%, 0.6 %, 0.9 % 1.2 % and 1.5%) of Banana fibre nanoparticles into base fluid (DI water). A Vibro Viscometer machine (SV-10) is used to measure the viscosity of the prepared nanofluids more conveniently. For minimum and maximum volume fractions of Banana fibre-nanoparticles (0.3% and 1.5%) in deionized water,the viscosity was found to be 1.08 mPa.s and 1.23mPa.s, which increases slightly with an increase of particle volume fraction and decreases as the temperature increases.The experimental results show a maximum of 22% increasing of viscosity for 1.5% volume fraction of nanofluids as compared with the deionized water (base fluid). From the experimental study on prepared nanofluids conducted, results show that all the values of viscosities at different volume fractions of the prepared nanofluids were found to be substantially higher than the values of the base fluids (deionized water). The experiments were conducted at varying temperature range (20oC through 60oC).Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016